System and Arrangement for Production and Insertion of a Dental Bridge Structure

ABSTRACT

A system comprises a computer appliance ( 7 ) designed to receive, and to present on screen, first information ( 12 ) transmitted from identification equipment ( 6 ) and based on detection of a jaw bone structure. Modification information which can be introduced into the computer appliance shows a visual dental bridge structure applied on the jaw bone structure with associated teeth and dentine. Orientations for implants are also shown. The computer appliance produces a CAD file which is based on the first information and the modification information. The file is received in a stereolithography machine which issues second information which can be processed in the equipment ( 9 ) for production of the physical template with associated through-bores for sleeves which determine recessed positions and directions for the implants. A working model ( 16 ) is produced with the aid of the physical template which is also used for hole formation in the jaw bone structure. The invention also relates to an arrangement of a template produced by stereolithography and by means of information from the computer appliance. By means of the invention, the installation of the dental bridge on the patient can be increased at lower cost, with shorter times and a sustained degree of accuracy.

The present invention relates inter alia to a system for production andinsertion of a real dental bridge structure in a real jaw bone structureby means of a number of successive function steps effected by equipmentbelonging to two or more different parties. The equipment comprisesidentification equipment, computer appliance, stereolithographyequipment, equipment for production of a physical template, equipmentfor production of a working model in cooperation with an articulator,equipment for production of the dental bridge structure and insertionequipment for fitting the dental bridge structure on the implant in thejaw bone structure. Jaw bone structure can here relate, for example, tothe structure of the upper jaw or lower jaw. The invention also relatesto an arrangement of a template produced by stereolithography and bymeans of information from the computer appliance and used for producing,on the one hand, a dental bridge structure that can be applied on animplant in the jaw bone structure, and, on the other hand, for guidingof hole-forming means, for example a drill, for forming holes for theimplants.

Systems of the type in question are already known, and reference may bemade inter alia to the patent application SE 0004884-3 filed by the sameApplicant.

It is also already known to use templates on the one hand for formingholes in the jaw bone structure and on the other hand for producingdental bridges. Reference may be made to the procedures used hitherto inthe dental field and to the arrangements which in principle are based onquite considerable manual skill. Reference may be made to SE 0004885-0,SE 0004886-8, SE 0104431-2, SE 0104432-0, SE 0203898-2, SE 0203899-0 andSE 0203900-6.

There is a distinct need for improvements to the procedures andarrangements/auxiliaries which have been used hitherto, for example fromthe point of view of time and cost. Thus, for example, the production ofthe template should be able to be reduced by 30-50% and, inter alia, thetime of use in the stereolithography machine should be able to bereduced. Despite the reduction from the point of view of time and cost,the precision of the produced products/dental bridges must remain high,as must the securing function, which must be maintained with tolerancesof ca. 0.1-0.2 mm. The system and the arrangement must also benon-critical from the handling point of view so that excellentproduction and insertion results are achieved. In addition, certaintime-consuming and cost-intensive operations must be eliminated, and,for example, the source of error in replacing a prosthesis or workingmodel in the correct relation to the jaw bone is to be eliminated.

The invention aims to solve these problems inter alia.

In accordance with the invention, the remaining operations too must becharacterized by well proven and non-critical techniques which can bedealt with and performed by parties already operating on the market. Theparties must be able to cooperate in an optimal manner from thetechnical and financial aspect. The number of parties must be able tovary and the functions must be able to be divided into testing,insertion and handling technique, production by means of STL(sterolithography technology) and model production, and production bythe dental technician. For support and possible production of one ormore of the functions, higher-order parties may be used who provide afully automatic production system for dental products, for example ofthe PROCERA® type.

The invention aims to solve this problem too.

That which can principally be regarded as characterizing a systemaccording to the invention is inter alia that the computer appliance isdesigned to receive, and to present on screen, first informationtransmitted from the identification equipment and based on detection ofthe jaw bone structure. The computer appliance is arranged withoperating elements by means of which it is possible to visually entermodification information concerning, on the one hand, a visual dentalbridge structure applied on the visual jaw bone structure withassociated teeth and dentine, and, on the other hand, orientations ofthe implants in the visual dental bridge structure and visual jaw bonestructure. Moreover, the computer appliance is arranged to produce or tocause generation of a CAD file based on the first information and themodification information and to transmit the CAD file to thestereolithography machine. The latter must be arranged to issue secondinformation which can be processed in the equipment for production ofthe physical template with associated through-bores for sleeves arrangedto determine the recessed positions and longitudinal directions for theimplants. The physical template will on the one hand form the basis forproduction of the working model and, on the other hand, serve astemplate in a hole formation defined with the sleeves and situated inthe real jaw bone structure by means of the insertion equipment (drill).

The identification and computer appliances can be assigned to a firstparty consisting of a party treating a patient, for example a surgeon ordentist. The stereolithography machine can be assigned to a secondparty. The equipment for production of template, working model and realdental bridge structure can be assigned to a third party, for example adental technician. A fourth party with equipment of a higher order canalso be involved, which fourth party can ensure information provisionand/or handling or production of one or more of said functions or partsthereof. The stereolithography machine can be accessed by any of saidparties. Further embodiments of the system according to the inventionare set out in the attached dependent claims concerning the system.

An arrangement according to the invention can be considered to becharacterized by the fact that the template and the dental bridgestructure are provided with through-holes, and the through-holes areprovided with sleeves by means of which the degrees of recessing of theimplants and orientations in the implants can be determined.

In further developments of the inventive concept, the sleeves aredesigned with special features for being able to achieve the relevantdegree of recessing in the template. In one embodiment, the sleeves canbe anchored with dental cement. In a preferred embodiment, the templateis arranged to reproduce or comprise a material or part whichcorresponds to the dentine or gum replacement over those parts whichextend over the jaw bone, in which the dental bridge is intended toextend. The template is produced in said machine from plastic materialwith very low coefficient of shrinkage. Further illustrative embodimentsare set out in the attached dependent claims concerning the novelarrangement.

By means of what has been proposed above, after fixture planning, theplanning files can be converted to CAD files and SLA models (rapidprototyping) can be ordered in so-called STL technology. Part of themodel can simulate the patient's upper jaw or lower jaw, while anotherpart simulates the patient's dental prosthesis. Thereafter, the workingmodel is produced at the dental laboratory. The template can be plannedon computer using CAD and contains all data information, which meansthat a template can be ordered with the aid of STL technology. When thetemplate is produced in physical form, it can be provided with sleevesfor guiding the drill, implant and anchoring pins. The sleeves can becemented in place with dental cement.

Thereafter, the template can be used as an impression for production ofthe working model in plaster, which is mounted in an articulator withthe aid of a bite index against the dental model of the opposite jaw/jawbone. The dental bridge can be produced on the working model obtained.The template also forms the gum replacement over the implant in the jawbone and around the spacers in connection with production of the workingmodel.

A presently proposed embodiment of a system and an arrangement accordingto the invention will be described below with reference to the attacheddrawings, in which

FIG. 1 shows, in block diagram form, the equipment and parties involved,

FIG. 2 shows, in side views and horizontal views, and enlarged inrelation to FIG. 1, parts of the function chain according to FIG. 1,

FIG. 3 shows, in vertical section, two different embodiments of sleevesused in the template,

FIG. 4 shows, in vertical section, application of a sleeve in relationto an implant, and a fastening screw for the sleeve and the implant,

FIG. 5 shows, from underneath, a model of an upper jaw in which implantsare applied with associated anchoring tubes and anchoring pins whichextend horizontally in the dentine between the implants,

FIG. 6 shows a top view of the model according to FIG. 5, and

FIG. 7 shows a perspective view, from the side, of orientations forimplants and anchoring pins in an upper jaw.

A template can be built up on computer using CAD by modifying thescanned patient prosthesis. In this way, it is possible to avoid theproblem of having to produce the template at a dental laboratory, andthis is an advantage since the template there is made of acrylic or of aplastic which has a certain shrinkage tendency, with deterioration ofthe precision as a consequence. According to the invention, the templatecan be mounted in the articulator with the aid of a bite index. In thisway, it is possible to solve the problem of recording the biterelationships of the jaws. The template is used by the surgeon andsolves the problem of placing the implant at the planned site in thepatient's mouth. The template has an arrangement for its anchoring withanchoring pins which are inserted from the side between the plannedimplants. In this way, the template is held in place in the mouth withthe aid of a bite index which is produced by the dental technician inthe articulator. This solves the problem of obtaining the correct biterelationship between the dental bridge and the opposite jaw after theoperation. The template contains all data for planning, so that it isnot necessary to produce the bone part of the patient's jaw. Thisreduces the production time and costs in the stereolithography machine.The source of error in the form of having to place the prosthesis modelin the correct relationship to the bone part is eliminated.

In FIG. 1, a first party is indicated symbolically by 1, a second partyby 2, and a third party by 3. The first party can be a surgeon, dentist,etc., who is to test and fit a dental bridge on a patient 4. The secondparty can be an owner of a stereolithography machine. The third partycan be a dental technician. FIG. 1 also indicates a fourth partyrepresented by a fully automatic production system for dental products;in the illustrative embodiment the party 5 is designated as PROCERA®.The first party has access to identification equipment 6. In addition,the first party has access to a computer appliance 7. Thestereolithography machine is symbolized by 8. The dental technician hasaccess to equipment for production of a physical template 9, andequipment 10 for production of a working model in cooperation with anarticulator function. In addition, the dental technician produces thefinal dental bridge in equipment 11.

The identification equipment 6 can be of a type known per se. Thus, forexample, the party 1 can produce an impression in a manner known per seusing conventional means. Alternatively, cameras, laser equipment, etc.,can be used. The computer appliance 7 comprises, in a manner known perse, a computer screen 7 a and an operating element 7 b which can consistof a keyboard, voice communication unit, etc.. Depending on theidentification, the relevant jaw/jaw bone, in this case upper jaw, ofthe patient 4 can be indicated. The upper jaw structure is symbolized by7 c. In addition, the first party can modify the jaw bone structure onthe screen and build up a dental crown structure applied on the jawbone. Such a structure is indicated by 7 d. For the sake of clarity, theupper jaw 7 c and the complete structure 7 d have been shown as twosimultaneous representations. Said representations can of course beindicated one at a time. In the representation 7 d, the orientations forthe implants and their directions are shown by 7 e. The computerappliance can operate with conventional programs (CAD programs), whichare available on the market, and file management systems. Thestereolithography machine can be of a type known per se and willtherefore not be described in detail here.

The scanning equipment 6 provides the computer appliance with firstinformation 12 which represents the scanned jaw bone structure. This isexported to the computer appliance. In turn, the computer appliancegenerates a CAD file which is represented by 13 in FIG. 1. The CAD fileis received by the stereolithography machine which sets the conditionsfor a physical model transferred to the dental technician 9 forapplication of sleeves, inter alia. This transfer is represented by 14.The physical model is shown by 15. The dental technician uses the model15 for production of a working model 16, and the transfer functionbetween the units 9 and 10 is symbolized by 17. The production of theworking model takes place in conjunction with an articulator functionwhich is represented by 18. The bite index for the articulator functioncan be transferred from the patient 4, the computer appliance 7 and/orthe identification equipment 6. Said transfers are represented by 19, 20and 21. At entry to the articulator function, the bite index transferhas been symbolized by 22.

The real dental bridge 23 is produced in the equipment 11 by the party3. From the equipment 9, the physical template 15 can be transferred tothe surgeon or equivalent. This transfer is represented by 24. The party1 can also have access to equipment symbolized by 1A. This equipment canconsist of drilling equipment and insertion equipment for fitting thetemplate and dental bridge on the patient 4. The finished dental bridgecan be transferred to the first party, as has been represented by thetransfer arrow 26. Formation of holes in the patient's jaw bone with theaid of the template and insertion of the finished dental bridge can takeplace in a manner known per se and will therefore not be described indetail here.

In accordance with FIG. 1, the fourth party 5 can provide a supportfunction or production of one or more of said function steps. This isshown in the figure where the automatic system comprises adaptationunits 27, 28, 29 and 30. The equipment of the other parties can also beconnected via adaptation units 31, 32, 33, 34, 35, 36, 37 and 38. Thetransfers can take place via general communication means 39, for examplethe telecommunications network, Internet, computer network, etc. Thetransfer functions are represented by two-direction arrows, whichindicates that two-way communications exist. The arrows are representedby 40.

In FIG. 2, an upper jaw of a patient is indicated by 41 and a lower jawby 42. In the upper jaw, the party 1 has inserted implants 43 in which adental bridge is to be secured. A set of teeth in the patient's lowerjaw is indicated by 44 and, in accordance with what has been explainedabove, the bite relationship between the dental bridge to be implantedand the teeth of the lower jaw has been effected with the aid of a biteindex. Reference number 45 indicates a template in accordance with theabove. The template comprises, inter alia, recesses 46 for sleeves 47used as guide members for formation of holes 48 in which the implants 43are to be screwed or recessed. Reference number 49 indicates thefinished dental bridge structure to be anchored on the implants 43 inthe upper jaw. The upper jaw is also shown diagrammatically fromunderneath by reference number 50 in order to indicate orientations foranchoring pins 51 which extend substantially in a horizontal plane inthe jaw structure. FIG. 3 shows a first embodiment of a sleeve 52 whichis used for guiding a drill 53 for forming the implant hole 48. Thesleeve has a stop edge 52 a which can cooperate with the template 54 viaa stop surface 54 a on the latter. FIG. 3 also shows a second embodiment55 of a sleeve 56 which is provided with slits 56 a. The template 57 inthis case has an internal recess 57 a into which a snap-fit flange 56 bon the sleeve can snap when the sleeve assumes its final position in thetemplate 57. A click noise function can be provided.

FIG. 4 shows an implant 60 applied in a jaw bone and dentine 59. Theimplant can cooperate with an attachment part 61 over which a sleeve 62in accordance with the above can be engaged. The components can be heldtogether with a retaining screw 63. The sleeve 62 is mounted in thetemplate or dental bridge part which is indicated by 64. The parts areshown in the disassembled state for the sake of clarity. The parts canbe joined together in the direction of the arrow 65. A through-hole inthe template 64 is shown by 64 a. Cement which is used for securing thesleeve to the template is shown symbolically by 52 b.

A structural configuration of a physical template is indicated by 66. Inthe present case, implants 67 are screwed securely to the template,compare with FIG. 4. The pins for anchoring are shown by 68. FIG. 6shows the template according to FIG. 5 from underneath. The anchoringpins 68 are designed with manual actuating members by means of which thepins can be screwed through the jaw bone in question. The figure showsthat the anchoring pins extend between the implants 67.

FIG. 7 shows, from the side and in perspective, the template accordingto FIGS. 5 and 6 applied to a jaw bone 69.

The invention is not limited to the embodiment described above by way ofexample, and instead it can be modified within the scope of the attachedpatent claims and the inventive concept

1. A system for production and insertion of a real dental bridgestructure (23) in a real jaw bone structure by means of a number ofsuccessive function steps effected by equipment belonging to two or moredifferent parties, said equipment comprising identification equipment(6), computer appliance (7 a, 7 b), equipment (8), equipment forproduction of a physical template (15), equipment for production of aworking model (16) in cooperation with an articulator (18), equipmentfor production of the dental bridge structure and insertion equipment(25) for fitting the dental bridge structure on the implant in the jawbone structure, wherein the computer appliance is designed to receive,and to present on screen, first information transmitted from theidentification equipment and based on detection of the jaw bonestructure, wherein the computer appliance is arranged with operatingelements by means of which it is possible to visually enter modificationinformation concerning, on the one hand, a visual dental bridgestructure applied on the visual jaw bone structure with associated teethand dentine (gum), and, on the other hand, orientations of the implantsin the visual dental bridge structure and visual jaw bone structure,wherein the computer appliance is arranged to produce a CAD file (13)based on the first information and the modification information and totransmit the CAD file to the stereolithography machine, wherein thestereolithography machine is arranged to issue second information whichcan be processed in the equipment for production of the physicaltemplate with associated through-bores for sleeves arranged to determinethe recessed positions and longitudinal directions for the implants, andwherein the physical template (15) on the one hand forms the basis forproduction of the working model and, on the other hand, serves astemplate in a hole formation defined with the sleeves and effected inthe real jaw bone structure by means of the insertion equipment.
 2. Thesystem as claimed in patent claim 1, wherein the identification andcomputer appliances (6, 7 a, 7 b) are assigned to a first party (1)consisting of a party treating a patient, for example a surgeon, whereinthe stereolithography machine is assigned to a second party (2), andwherein the equipment for production of template, working model and realdental bridge structure is assigned to a third party (3), for exampledental technician.
 3. The system as in claim 1, wherein the appliancesassigned to the various parties can be connected to equipment of ahigher order belonging to a fourth party (5) for information provisionand/or handling or production of one or more of said functions or partsthereof.
 4. The system as in claim 1, wherein the equipment forproduction of a working model (16) in cooperation with an articulator(18) is arranged to receive bite index information (22) from theidentification equipment, the computer appliance and/or the equipment ofhigher order.
 5. The system as in claim 1, wherein the computerappliance (7 a, 7 b) and/or the equipment for production of a physicaltemplate is/are arranged to indicate positions between the implants forfixing members, for example fixing pins, which extend through the jawbone structure for retention in or on patient (4) in the hole formationfor implants.
 6. An arrangement of a template produced bystereolithography (14) and by means of information from computerappliance (7 a, 7 b) and used for producing, on the one hand, a dentalbridge structure that can be applied on an implant in the jaw bonestructure, and, on the other hand, for guiding of hole-forming means(drill) (25) for forming holes for the implants (7 e), wherein thetemplate (15) and the dental bridge structure (23) are provided withthrough-holes, and wherein the through-holes are provided with sleevesby means of which the degrees of recessing of the implants andorientations in the implants can be determined.
 7. The arrangement as inclaim 6, wherein the sleeves are arranged with first members (52 a)which determine their degree of recessing in the template and which, inthe recessed position, cooperate with corresponding second members (54a) in the template.
 8. The arrangement as in claim 7, wherein the firstmembers (52 a) consist of outwardly projecting flanges and the secondmembers (54 a) consist of stop surfaces.
 9. The arrangement as in claim6, wherein the sleeves are arranged with resilient members (56 b) whichdetermine their degree of recessing in the template and are designed tobe able to be snapped into an internal recess (57 a) in the finalposition of the sleeves.
 10. The arrangement as in claim 9, wherein theresilient members (56 b) are arranged to emit a click sound when therespective sleeve reaches its final position in the template.
 11. Thearrangement as in claim 6, wherein the respective sleeve (62) can beanchored or locked by means of cement
 12. The arrangement as in claim 6,wherein first sleeves (52) are arranged for guiding the drill andimplant or determining directions in which the drill (s) will operate inthe respective implants, and second sleeves (51) for anchoring membersor pins which are designed to extend horizontally through the jaw bone.13. The arrangement as in claim 6, claimed in any of patent claims 6-12,wherein the template (15) is arranged to reproduce or comprise amaterial or part which corresponds to the dentine or gum replacementover those parts which extend over the jaw bone, in which the dentalbridge is intended to extend.
 14. The arrangement as in claim 6, thetemplate is made of, plastic material with a low coefficient of creep.15. The arrangement as in claim 6, wherein the template has aconfiguration which precisely or clearly fixes the position of thetemplate on the jaw bone (58,59) in order to permit hole formations, forthe implants, which very accurately match the hole formations in theproduced dental bridge (23), and the accuracy can be 0.1-0.2 mm.
 16. Thearrangement as in claim 6, wherein the finished dental bridge (23) isdesigned to cooperate with teeth (44) in the opposite jaw bone with theaid of bite index added to the template and dental bridge.
 17. Thearrangement as in claim 6, wherein said material or part of the templatewhich corresponds to the dentine or gum replacement is designed toreduce the template production time in a stereolithography machine (8),inter alia, by compared to the case where the working model is replacedin the correct relation to the bone part.